Figure 3

A schematic representation of MDMA’s sites of action in the Hippocampus. This figure summarizes the effects of a single-dose (15 mg/kg, intraperitoneal) of 3,4-methylenedioxymethamphetamine (MDMA) 3 weeks earlier on hippocampal neurons in Dark Agouti rats. Three distinct processes were identified marked by text boxes on the figure, phosphorylation- and dendrite development-related gene sets and gene sets involved in the proper synaptic functioning were downregulated (signed with red crosses at possible sites of action). These processes can be bound to memory and cognition gene sets (downregulated alike) through a single mediator, namely the type 1 cannabinoid receptor (CB1). Accordingly, single-dose MDMA administration 3 weeks earlier resulted in elevated CB1 mRNA levels in the hippocampus. It has to be noted that compared to the frontal cortical region (Figure 5), where rather intracellular signaling mechanisms were influenced, in the HC gene sets related to the connectivity of neurons were damaged. See text for further details.